Reader Brendan Keough writes in with the following:
Yep, I got this in the mail last Friday and finished it that evening. I'll likely play it again before the retail version ships. One point of interest you didn't mention: once you finish the last level on the menu there is another, hidden level that has you fighting Wagner (not sure if that's his name, the dude with the red eyes and the fancy mech) on a German castle. To access the hidden level, finish all demo levels and move the cursor down past the last choice, the cursor will disappear under the copyright but you'll hear a navigation beep. Hit X and have fun (watch out for the artillery, large area effect explosions)!
(CW)TB